Battery charger compatibility

[ORIF]

I have 3 lead acid 8 D's
Each of my Cat 3208s has a dedicated starter 8D
1 is house and supposedly "deep cycle"

My charger is 2 Xantrex 40 amp TrueCharge 2's wired to provide 80 amps.

This charger charges all 3.

It's time to replace the house bank.

Question is, if I replace the current house 8D with 2 6V golf cart lead acid batteries in series, would this still be compatible for the charger?

Thanks

 

[SteveK]

do you have current battery specs as to type to confirm at least one is deep cycle and the other two are start, I gather you have twin engines.

I have one 8D starter for two engines as it is can handle the starting one at a time and then starting the engine that has a dedicated alt charger to this battery.

My thoughts are if all three are the same and one has worked for house then one of the start ones can be used to replace the house one. Longshot maybe.

I also do not see only 2-6V house being adequate, but that depends on the load and how often you use it.

The chargers will still work

 

[Comodave]

If they are all lead acid batteries you should be fine.

 

[tiltrider1]

I have 3 lead acid 8 D's
Each of my Cat 3208s has a dedicated starter 8D
1 is house and supposedly "deep cycle"

My charger is 2 Xantrex 40 amp TrueCharge 2's wired to provide 80 amps.

This charger charges all 3.

It's time to replace the house bank.

Question is, if I replace the current house 8D with 2 6V golf cart lead acid batteries in series, would this still be compatible for the charger?

Thanks

Your chargers are two bank chargers. You have 3 batteries. I'm guessing that charger one has one leg going to each start battery and that charger two has both legs going to the house battery. This would give you 20 amps on each start battery and 40 amps on the house battery.

 

[Bacchus]

What I would do depends on usage & cruising style.
Agree that one batty bank could start both engines and house bank seems small.

If current house 8D is adequate you must spend very little time w/o shore power. Two 8Ds for house is what I have now. If using FLA 4 - 6V GCs would be my choice.

2 GP 31s are more than adequate for starting. If you don't have a 1-2-all batty switch I would add one as a back up just in case you need to boost for start.

4 - GCs are certainly capable of starting in an emergency.

 

[ORIF]

Your chargers are two bank chargers. You have 3 batteries. I'm guessing that charger one has one leg going to each start battery and that charger two has both legs going to the house battery. This would give you 20 amps on each start battery and 40 amps on the house battery.

This is a 3 bank charging system

 

[ranger58sb]

Question is, if I replace the current house 8D with 2 6V golf cart lead acid batteries in series, would this still be compatible for the charger?

Chargers mostly don't care about BCI Group; instead they're mostly focused on voltage. OTOH, capacity can be a factor, too.

In this case, if you replace with a pair of 6Vs that want the same charging voltage, no problem. If they're 6Vs that need a different charging voltage, then it's probably worth some more study. Look up what charging voltages are recommended for your 8Ds, the available voltage settings on you charger, and the voltage recommendation for your target 6Vs. They don't have to be exact, but you don't want to be significantly overcharging any given bank.

A typical 8d will give you a capacity of approx 245 Ah. A typical pair of 6Vs will give you a capacity of approx 220 Ah. That's probably not enough difference in bank capacity to cause your charger any grief. (Sometimes, for example in a 3-bank set-up with two large banks and one small genset battery, the small battery can be overcharged a bit.)

Depending on actual batteries, you may be reducing yur house bank capacity.

-Chris

 

[tiltrider1]

The answer to OP’s question is you need not worry about the charger capability if you change from 8D to 2 GC in series. The charger is engineered to deal with the mixed lead acid battery types.

In my opinion what you need to be concerned with is the poor quality construction that comes with the Xantrex name. I bought one of theses chargers as a back up charger. It didn’t last a year for me.

 

[SteveK]

............................

In my opinion what you need to be concerned with is the poor quality construction that comes with the Xantrex name. I bought one of theses chargers as a back up charger. It didn’t last a year for me.

Interesting. We just had a thread about poor quality out of China, and now you dish Made in America. Lasted one year and a day and missed the warranty replacement. Come on, there must be more to the story

 

[tiltrider1]

Interesting. We just had a thread about poor quality out of China, and now you dish Made in America. Lasted one year and a day and missed the warranty replacement. Come on, there must be more to the story

I don't bash a product based on were it is made. It is my opinion that Xantrex builds a product to a price point and the corners they cut to get to that price point make the product un reliable. Trace made inverter chargers so good that they still function like new after 25 years of use. Xantrex bought Trace and reproduced the same product under the Xantrex name but in my opinion they started cutting corners and the product is no longer as reliable.

I bought a Xantrex TrueCharge 2 40 amp model as a back up charger. I liked its small size and it was by far the cheapest 40 amp charger on the market. As a back up charger it was used very little, maybe 200 hours. Six months in I went to use it and it was dead. I replaced it with a Victron 40 amp charger. Cost 50% more but it is still working 1 year later. This is my experience with Xantrex and such will be the reason for my low opinion of their products.

 

[SteveK]

Tilt, we have all bought a lemon of some kind or another. At 6 months you should have received a replacement or repair. Fact is many have Xantrex without worry. I have a Xantrex inverter/charger. Yes it had a failure and warranty repaired it. That said should it fail again and out of warranty I will buy another brand for peace of mind which is not often found which products made cheaper to satisfy our lust for the best price.

 

[Jeff F]

I had two truecharge2 40 amp units fail in my last boat. First after about 5 years, second in two. I wasn't impressed.

 

[Mischief Managed]

I have 3 lead acid 8 D's
Each of my Cat 3208s has a dedicated starter 8D
1 is house and supposedly "deep cycle"

My charger is 2 Xantrex 40 amp TrueCharge 2's wired to provide 80 amps.

This charger charges all 3.

It's time to replace the house bank.

Question is, if I replace the current house 8D with 2 6V golf cart lead acid batteries in series, would this still be compatible for the charger?

Thanks

AS others have stated, your charger will have no trouble with what you propose.



I have the same boat with the same engines as you. I completely re-engineered my battery bank and charging design earlier this year. I now use 6 205 AH GC batteries for the house bank and one 8D for starting both of my 3208s. I also have one FLA Group 27 for my genset. All are flooded lead acid and were purchased new by the seller a week before I closed on the boat in May 2019 (the old batteries were no good due to a failed 1992 vintage charger).



I ditched the factory battery isolator and in it's place is a Blue Sea Sytems 500 amp ACR between the house and main starting banks so that both are charged whenever either bank is being charged. The ACR also allows me to parallel both banks from the helm if I need to augment my 8D starting battery. That said, my Tolly 44 had a factory "Start Assist" feature that paralleled the house and starting bank from the helm before I by-passed it in favor of the ACR for the same function.



I have a Promariner 1250P 3 bank 50 amp charger that is connected to the main starting battery, the house bank, and the genset battery. My Xantrex Freedom 3012 inverter charger also charges the house bank, but it is throttled to 100 amps to keep the charge current from damaging the house batteries. When the house batteries are in need of bulk charge, I only use the inverter to charge them.



When my FLA batteries are worn out, I intend to replace them with AGMs to allow faster re-charging. With AGMs, I can run the Zantrex at it's full 150 amps and Promariner at 50 amps at the same time, without damaging the batteries. This will dramatically reduce charge time.



I'm in the midst of rebuilding my engine room battery tray right now. It was pretty tired after 30 year. I may try to slide it to starboard a few inches to help with my boat's natural list to port.



If you'd like to discuss any of this, feel free to IM me. I learned a ton while coming up with my new design and I am pleased to say it worked better than anticipated all last year.

 

[mvweebles]

Question: How useful is a 225 AH FLA house battery bank on a 44-foot boat? I had 6xGC FLA so roughly 650AH and felt that was only adequate and replaced with 700AH of LiFePO4. On my standard Ford-sized campervan, I had 2xGC (225AH) FLA which was marginal so I replaced with LiFePO4

Just seems like for a 44-footer, 225AH FLA is pretty thin.

Peter

 

[SteveK]

Question: How useful is a 225 AH FLA house battery bank on a 44-foot boat? I had 6xGC FLA so roughly 650AH and felt that was only adequate and replaced with 700AH of LiFePO4. On my standard Ford-sized campervan, I had 2xGC (225AH) FLA which was marginal so I replaced with LiFePO4

Just seems like for a 44-footer, 225AH FLA is pretty thin.

Peter

That was my first thought as well, toast and coffee and batteries need a charge.
A single pair will work for a day IMO.

I installed 4-6V and since added 2 more, with thoughts of another 2.Then there is recharge ability that will limit how many as well. I want to anchor for more than 1-2 days at a time.